Figure 3: AM with coiled-up space for composing the sound insulator.
From: Sound Insulation in a Hollow Pipe with Subwavelength Thickness
Distribution of acoustic pressure of the scattered wave field produced by the anomalous reflection on the AM for (a) grazing incidence and (b) normal incidence cases. Propagation direction of scattered wave is marked by white arrows and the incident wave is not shown in the figures. (c) Simulated distribution of pressure amplitude in a model with four periods (N = 4) of unit cells on each side at 4346 Hz. (d) Comparison between the frequency dependences of the sound intensity transmission for three cases with different periods, i.e., N = 4, 6 and 9.
